Changing the Future
by AnHeiressofaSOLDIER
Summary: Upon playing Final Fantasy XIII-2, and seeing Serah die for changing the future, Jace fears that Clary may die the same way. With the light of hope in her heart, Clary shows Jace that when prayers turn to promises, not even fate can stand in their way.


**Author's Note: You probably will have had to play Final Fantasy XIII-2 (and the original Final Fantasy XIII) to understand this one-shot (though you could probably just watch the English ending of XIII-2 and get most of this). This story has MAJOR spoilers for XIII-2's ending, so be warned. I hope you all enjoy. Also, this takes place after City of Fallen Angels, but is somewhat AU because Jace isn't possessed by Sebastian. On with the story!**

**Changing the Future**

"I know it's dangerous Simon, but if you don't go all out when attacking, you'll lose in the long run!" When Simon didn't seem to have any desire to follow Clary's advice (and just kept on healing), Clary thought it was high time she stole his controller away and show him exactly what he was doing wrong.

Which she did. Clary's breath hitched when she felt Jace shuffle closer to her. It was indeed a mystery as to why he'd decided to come over while Clary was hanging out with Simon, but it was even more surprising that Jace hadn't yet remarked on their nerdy behavior. Instead, he'd actually moved closer to his girlfriend. That was flattering, at least. It hadn't been much earlier that the Shadowhunter had (accidentally) insulted Clary by dissing Simon's World of Warcraft friends.

But this wasn't World of Warcraft. This was a game much closer to Clary's heart. A game that she, really, needed to pay attention to! Simon gave Clary a smug look when her distractions forced her to go on the defensive. Switching Serah, Noel, and their monster all to Sentinel, Clary threw a few potions on her party members before switching back to Relentless Assault. Noel and the (new) monster were now attacking relentlessly. Clary, not wanting Bahamut to become un-staggered, did something risky. She used Serah's Ultimate Arrow ability. Usually she wouldn't. Since this ability took so long to load, it usually left her wide open (and made the stagger bar decrease). It didn't even always do a lot of damage, but she was desperate, damnit! And her desperation led to success. Simon gaped, as Clary placed the final hit; after seeing how many stars she'd gotten, the ending cinematics began to roll.

"Unbelievable!" Simon complained, as he slapped his forehead and sat back on his couch (but not before stealing his Playstation 3 controller back from Clary). "I didn't think you'd actually defeat Caius! Damnit, Clary, now I can't say that I beat the game!"

Jace laughed loudly and with mirth at Simon's expense. As Clary and Simon both shot Jace a look (Simon in irritation and Clary in question), Clary had to wonder if he was just trying to hide the fact he knew nothing about RPGs by seeming all too amused. Or maybe he just really enjoyed watching Simon squirm. Clary was inclined to think it was the latter. Trying to mend Simon's wounded ego, Clary reached up (as she was sitting on the floor) to pat her friend's shoulder sympathetically. "You can always just reload your last save and beat him yourself. Now shut up, I want to watch this!"

And the three friends did watch the ending, engrossed. Clary knew that Simon, though a little bit irked, was actually psyched to see the ending of Final Fantasy XIII-2. He had been fighting against Caius to reach this part, after all. And Clary, too, was taken away by it all. She hadn't yet gotten this far in the game (having a boyfriend _was_ distracting), but she was close to it. In the end, she opted to watch it because there wasn't that much left that she hadn't seen. And Jace (if not just indulging Clary) was probably just awed by the graphics. Clary had to admit they were nice, but she wished there were more fully rendered scenes like in the first one. And better motions. If she saw Noel put a hand under his chin one more time...

"Crap!" Clary exclaimed, as a surprise Cinematic Action appeared on the screen. As Simon was a bit away from her, she knew she wouldn't be able to react to it, but neither would Simon, it seemed. He was too into the story, and was only now realizing he was supposed to be pressing something. Surprisingly, it was Jace who stole the controller away from Simon. He pressed square, as he chose to "show mercy" to Caius, and probably saved Simon or Clary from having to do the entire final battle again. Relaxed now, Clary turned to face Jace with a raised eyebrow (at least an attempted raised eyebrow), "I'm surprise you'd choose to 'show mercy'?" Clary's uncertainty made her words sound more like a question than a statement of fact.

Jace, graciously, chose to sit down beside Clary so they could talk easier. For a moment, Clary was lost in the beautiful golden eyes and curly hair of the love of her life. She longed to reach out and run a hand through his shorter locks. She wanted to run her fingers over his lips, to kiss him- "'Square' was the first option I saw," Jace shrugged indifferently. With those words, Clary was pulled back to the present. With a shake of her head, she aimed to remove the lust filled thoughts from her mind. It would not be a good idea to act on them in Simon's room! "Jace," Clary began to warn. It was a habit, really. When they'd thought they were brother and sister, Clary had become so used to discouraging Jace's advances. She'd become so used to telling him why they couldn't be together. It was almost second nature to shoot him down at inappropriate times no-

"Will you two can it?" Simon groaned.

Clary's cheeks flamed, as she looked up towards Simon. Great. They weren't being as subtle as she'd thought! Sure Simon may have been over his feelings for her, but it was still unkind to want to kiss Jace when he was near. But what was worse was that she probably was looking like a tomato with her annoying red hair, freckles, and blush. Not wanting to find any other reason to become embarrassed (for many different reasons), Clary returned her attention to the game.

And became lost in it. And, by all honesty, quite shocked by it. She knew, for a fact, that her mouth was hanging open as much as Simon's had been earlier when the "Eyes of Etro" sign appeared in Serah's eyes. She knew what was coming, of course. But she was still taken aback when Serah began falling backwards. Noel grabbed onto Serah's hand and pulled her to his chest, but it wasn't enough. She fell backwards again, as her seizure pressed on. And when the character closed her eyes, Clary knew she'd never wake up. Sure enough, Serah ended up laying dead in Noel's arms, as Hope came forward and Noel had to explain how Serah had ended up being just like Yeul.

Quite honestly, it was the most infuriating ending Clary had ever seen, but she actually enjoyed it for some reason. She hadn't seen it coming. At all. Everything had been fine! Happy music had been playing, Serah had said she was fine (even more seeming to show she'd survive), and then she'd simply said, "Thank You." A minute was all it took for everything to change. For Serah to die.

Another thing that was hard to take in was how the villain had technically won! Looking back now, Clary thought she should have known he would. The characters had done what Caius had wanted them to, but the game had been designed (it seemed) for the player to forget Caius' words until they made it come true. It was some game all right (even crazier stuff happened, surprisingly, after Serah's death), and Clary wasn't entirely sure how she felt about it all at the moment.

"This game makes no sense," Jace said, surprisingly, just as moved by it as his friends. Somehow, his words seemed to sum up Clary's thoughts perfectly. Because even though it all did make sense, it was hard to wrap her head around. It really seemed as though the makers had tried to make the player feel unstable as the credits rolled.

Clary looked over to Simon a bit guiltily, as he just continued to gape at the screen. Clary wondered if Simon would have any desire to beat the game himself now that he'd seen such an ending, but there were supposed to be paradox endings...

"It makes sense," Simon argued with what seemed a knee-jerk-reaction. Clary, almost in response, got to her own feet and shifted her weight from one foot to the other uncomfortably. "She pretty much became a Seeress like Yeul. And since each time the Seeress sees a vision of the future, she loses a piece of her life..."

"You vampires are such prima donnas. It's just like what Magnus said." Simon seemed about to protest, as Jace also stood up if only to wrap an arm around Clary's waist, but Jace wasn't having any of that. "Because if she's really like Yeul, then she'll be alive again, like Yeul, in that secret ending. Well, Valhalla's equivalent of life I guess."

For a moment, Clary could only stare at Jace in shock. Honestly, she hadn't thought he'd been paying that much attention. And the thought that he had been warmed her immensely. If not for the fact that Jace and Simon were getting along in their own weird way, because he didn't seem to only be supporting her geeky behavior, but enjoying it somewhat. His approval on that one aspect of her life had never bothered Clary, and yet, she'd never felt so besotted to Jace.

Clary bit on her lip just for the bit of pain. It was not a good idea to think about such outlandish things. She ought to be paying attention to the matter at hand. "I like how you're so nonchalant about it," Clary said just to say something, even though the words never held weight to her. Of course, Jace would say it nonchalantly. He wasn't a gamer, and he still really knew nothing about the game.

However, Clary's words seemed to mean something to Simon. Clary's favorite musician laughed slightly, as he shut the game off, but only to get out his laptop to search for XIII-2 pictures on deviantArt. "Yeah. Your lack of faith that bad things can happen to the heroes indefinitely reminds me of someone."

Simon sent Clary a particular nod at the end of his words, but he needn't have. Even without the hint, Simon's words had made too much sense. And when they finally righted themselves, she had to laugh. "God, you're Snow, Jace! I guess you both have the recklessness, blond hair, and hero complex. Does that make me Serah?" Even though she wouldn't say it aloud, Clary knew that it did. After all, Serah was Snow's significant other, and he was her "hero". Clary chuckled a little more when she remembered how Simon had once said, "You acted like Jace was one of your heroes come to life." It seemed as though Simon had been right.

"I was only that way before I met you and found reason for my life, Clary." As Simon made a gagging noise in response, it didn't take a genius to figure out Jace was saying this in response to his once recklessness. Perhaps fearing that someone would argue he was _still_ restless, Jace stepped away from Clary slightly and seemed to be in deep thought. The red haired girl groaned when she saw he'd adopted to putting his hand under his chin as he paced. Ugh! Maybe he was like Noel, too! They _really _could have used more character animations in the game.

"You know, that 'Moogle's' annoying. It reminds me of Church for some reason. Does it hate Noel as much as Church hates me?"

Clary was about to reply to her boyfriend's random question, but Simon beat her to it. "Yep. The poor deceased Mog hated Noel so much, he decided to die in Hope's arms rather than Noel's. Tough luck, Jace. You're a mix of Snow and a less cooler Noel. Because I'm like Noel, too. But I'm a cooler Noel. Despite the fact that I actually look like him, I'm a cooler him because I wouldn't have let Serah die."

Looking back on it, Clary would eventually realize that it had been those words that had done it. But at the time, she couldn't understand why Jace's face contorted in shock. She couldn't figure out why he took one look at Simon's laptop before storming from his room furiously. Clary really couldn't figure it out. What was wrong? And why had Simon's laptop made things worse? He was only looking at a gif of that last sad, but beautiful, Noel and Serah scene. Simon seemed even more lost than Clary. "Did my joke have another punch line I'm unaware of?"

"I don't know," Clary replied instantly, but as she did, she hated herself for it. She sounded much too childish and docile. It reminded her of all the times Jace had said mean things, and she'd just let it affect her. She'd failed to fight for what she wanted for. She'd failed to see what lay beneath Jace's hateful words. The time after their first kiss, the Seelie Court, and Idris were all prime examples of this, but no more. She wouldn't let Jace leave in such a way ever again. "I should-" Clary began a lot more confidently.

"Yeah, go after Mr. 'prima donna'. I should call Isabelle, anyway."

With a slight shake of her head at Simon using Jace's earlier words against him (unknown to him), Clary bid her best friend adieu and went to look for Jace.

In the end, she wasn't surprised when she found him outside walking away from Simon's house. He was walking slowly, though. And though Clary thought he didn't want company, it seemed he didn't want to storm off as effectively as he had in the past. That was enough for her. If Jace wasn't shutting his doors completely, she'd be a fool to not pass through them.

"Jace!" Clary called, as she ran a bit to catch up with her "significant other". It was hot out, and even though her training as a Nephilim had toughened her up, Clary was already desperate to hail a taxi to take them to the Institute. She wondered at Jace's strength, as he didn't seem not only unaffected by the humidity, but also planning to _walk_ to the Institute at noon in this heat.

Once upon a time, Jace's stop wouldn't have meant anything to Clary. Not even when he turned around and muttered something about missing training with Maryse. But, really, it was the way he sheepishly scratched his neck that did it for Clary. If Clary could, she would have gone back in time just to smack her past self across the face. It was so, so clear that something was wrong with Jace. It was almost insulting that the old her wouldn't have realized it. Crossing her arms over her chest, and tapping her foot agitatedly, Clary set Jace with a stern look. She knew they were attracting attention from everyone who was milling past them (or trying to), but she couldn't care at the moment.

"Jace, do you really expect me to buy that? What do you take me for? You didn't leave Simon's like that for no reason. And that has got to be the lamest excuse I've ever heard. Like you need training with Maryse! And even if you did, you wouldn't care if you were a few minutes late. And you do _not_ do sheepis-"

Before she could rant any more, Clary suddenly found herself effectively silenced by the form of Jace's lips. As she always did, she found herself melting into his kiss, as she gripped Jace's arms a little too firmly. It was hard not to act aggressively, though, not with the way Jace was clutching her to him desperately. Not with how he was putting everything he'd ever felt for her into the kiss, as if asking her not to leave him. It was funny how before she'd been annoyed with the heat, but now she couldn't get enough of another kind. But it was for that reason she had to push him away. When Jace kissed her like this... it never led to anything good.

As if to answer her fears, Jace whispered something so brokenly, so unsure, so unlike himself... Clary had to wonder if he'd really spoken at all. "You changed the future, Clary."

Clary stood there numbly, as a gust of wind traversed past her, and allowed her to fill her suddenly parched lungs. Odd. She hadn't realized she'd stopped breathing. The air was good, though. It gave her a sense of clarity. Because, really, Jace couldn't have been that upset over a video game, but what else? What could be making him seem so anxious? "It's just a stupid game," Clary got out in a tone similar to the one Jace had just used. She was unsure about saying such a thing, but she thought maybe it would give her a hint about what was bothering her Jace. If he went on a tangent about the game, she'd know an alien had replaced Jace. If he were incredulous about her assuming that was what was bothering him... well, then hopefully he'd spill what his real problem was.

Even with her assurance to herself that she'd figure things out and help Jace, Clary would have never guessed that Final Fantasy XIII-2 had sparked his reaction, but only because it reminded him of something else. But, then again, if Jace wouldn't have been glaring at her angrily—the yellow of his eyes looking like burning embers—Clary might have been able to put it together before Jace relented angrily, "Every story is based in fact, Clary. You know that. And you've condemned yourself by saving me. I was supposed to die in Idris. I did die, but you changed the future. I've already dealt with the consequences, but what if you have to, too? What if I have to live without-"

It took Clary a moment to catch up with where Jace already was. And when she did, she could only lose her equilibrium as mystified as she was. Even though it wasn't a reaction she could control, it certainly wasn't helping matters. Jace caught her from falling, and brought her to sit down on the steps of some apartment, but she could feel his heart hammering in his chest. No doubt, he was thinking his worst fears were coming true. That she was dying in his arms the way Serah had Noel's. It was such a ridiculous thought, but it was kind of sweet that he cared so much.

But when Jace looked at her with nothing but fear in his eyes, Clary felt her temper flaring. He was going to get all emo about an idea a video game had come up with? After all they'd overcome, he was going to get up and arms over this? And who in the hell did he think he was to-

"Don't you think it's the same for me, too? I don't want anything else in the world, but you Jace Lightwood!" Clary said somewhat snootily, as she lifted her nose in the air, and glared down at her fellow Shadowhunter. Maybe the gesture would show him what a hypocrite he was being! Really! Of course she had had to bring him back. And of course, she didn't regret it! Jace was afraid he'd lose her now because of her action, but she'd really lost him. He had no right to assume that he knew what that was like. He had no right to scold Clary for saving his life. _He didn't know what it was like. _It had been in her power to save him, and she had. And she knew, even if he protested now, he would have done the same for her. They always would have saved each other because that was what people in love did.

"It's different, Clary!" As he looked down at her (using his superior height to do so), Clary realized his eyes were flashing just as much as hers had been. He was furious, and she realized a little remorsefully that she'd struck a nerve, but it didn't matter. He'd needed to hear it. He'd needed to hear what she thought. Even if she might have, slightly, been disregarding his own feelings on the matter. And if his anger was anything to go by, she'd underestimated a lot. At least she wasn't running away anymore. At least she was going to sort it all out. She just hoped that Jace would want the same.

"It's different, Clary," Jace said coldly. Clary winced. Even though she'd had more ample time to get used to Jace since they'd gotten together (good examples of "getting used to him" being how romantic he could be in their private time), Clary always felt more than a little small when Jace got like this. She could understand, though. He had a lot to work through, and the way he'd always thrown himself into battle often went hand-in-hand with how he employed his anger in a fight. "It's different because my life held no meaning before you. I was so lost and dead before Pandemonium. So eager to die in battle after my 'father' had been 'murdered'. But your life has always held meaning, Clary. 'If you change the future, you change the past.' What if that Noel character's right? Even if you don't die... Clary what if your actions created a Paradox? What if it took something precious from you and we can't even remember it? How could I live with myself, then? You're everything to me, Clary. It's you alone who showed me I have a sou-"

"And yet you think I could have let that beautiful soul leave me in Idris? How can you think that? How can you think I should have done just that?" Clary, before coming back from Idris, might have been surprised to hear herself talk like this. But Jace's words when they were like this... they always seemed to ignite something in her. Even though she was irritated at Jace's doubt in her own feelings, she was more touched by what he'd said. She was more touched than he'd ever know. How could this person have been raised by Valentine? How could someone that had once believed "to love is to destroy" say things like this? If Clary had ever needed proof that Jace was nothing like his father, and that her mother's fears were void, it was moments like this. Because even though he was broken, and his words couldn't exactly paint a picture, Clary could see the beautiful pieces of him easily. The angel girl closed her eyes blissfully, as she traced her hands over Jace's cheeks.

As Jace shuddered at her slight touch, Clary realized he was losing the fight to be a pessimist. But he had one more card up his sleeve. And as he said the words, tears leaked down Jace's eyes, but Clary's eyes bled, too. Their tears bled together until Clary couldn't distinguish whose were whose anymore. All the while, she held onto Jace's hand. He was her anchor and strength. No matter what he said. "Your love that draws me to you, that makes you stronger, also makes you reckless. In the end, it'll destroy you. Then I _will_ be like that Noel guy, Clary. Noel lost his father figure, Yeul... I'll lose you. I'll lose everything."

Clary fought the urge to tell Jace he'd forgotten to call her "Serah" while imagining himself as Noel. She also fought the urge to tell Jace that Noel was really in love with Yeul and Serah loved Snow. His comparison was flawed and silly, and in that, maybe silly was the course of action Clary needed. After all, there was no talking to Jace when he was in this state of mind. But if she could play off where he was...

"Jace, you really need to watch more Mundane things. In fact, XIII-2 is the first thing I've ever come across that says, 'if you change the future, you change the past', and not the other way around." Clary looked at Jace then, and upon seeing the slightly embarrassed and confused look on his face, she couldn't help, but wrap her arms around him and bury her face in the crook of his neck. He was so innocent in certain aspects. He was so _Jace_. And she wouldn't want him any other way. Still, she had to laugh slightly at how odd he was being. "The past is the past. Even if you were right, and we caused bad things to be set up for us... we can't do anything about it now. All we can really hope to do is pave a better future. To make every moment we have count. Because to love _is_ to destroy, Jace. When one of us dies, the other will be desolate, but that's the natural order of things. What matters is the good memories, and knowing you'll follow the one you love someday."

"You really think we could follow each other? That there's a God and afterlife and all that?" Clary knew that just because Jace had the Angel's blood in him, and had been raised as such for years, he was still as lost about religion as everyone else was. After all, he knew perhaps more and less than everyone. He knew that no religion was completely true, but there was truth in every one.

Clary had come to accept this, too. But even then, with absolute certainty, she was able to say, "Yes. I know my place will always be with you, Jace. You once thought you were a demon. That only a demon could love his angelic sister. And even though I'd never believed that, I'd been prepared to go to hell to be with you all the same. I would have gone wherever I had to to be with you. I still will. I always will."

"Clary, you just said dying and one day leaving your loved one is the natural order of things, but why'd you save me, then? It's kind of contradicting."

The Shadowhunter in training sighed, as she turned away from Jace's embrace, and put her hand under her chin (thankfully, her hands were almost folded in prayer, so it was unlike Noel and even Serah's annoying gesture). In all honesty, Clary wasn't sure she had the answer he was looking for. And even if she said what she thought was true, she knew it might not reassure Jace at all. Maybe nothing would, but she didn't want to be at an impasse with him, so she used her clasped hands as an example; she prayed that none of Jace—and her own fears—would come to pass.

With a new bout of strength, Clary regarded Jace with a sweet smile. "Because I'm human. And I had the opportunity. I didn't want to have to wait to be with you. And I wasn't going to have let Valentine do that to you after everything. But you know what else I think it was? Serah... she knew the risk when she chose to change the future. She knew her life was in danger, but she wasn't willing to let everyone suffer for her selfishness. Jace... you've saved so many Mundanes. And I know you'll continue to do so. I think I brought you back because I knew that. Because it was the right thing to do. And even if I die now... well, isn't it worth it? We all made pacts to protect the Mundanes even at the expense of our own lives. And even then, I think I wanted to do that. I think-"

Once again, Clary's words were cut off by a smoldering kiss, but this one was so much different than the earlier one. It was just as addictive, though. This kiss was warm, and sweet, and love incarnate. In this kiss, Clary felt like Jace understood where she was coming from, and why she'd done what she had. As he leaned his forehead against hers, and his sweet breath washed over her face, Clary felt as though he may have finally realized they really were the same, and would always be so in everything they did. They were just a normal couple in love, but they were so much more, too.

"I understand now, Clary. I understand. And I'm not going to waste anymore of our time with things like this. There's so much I need to get over, and this is really just a front, but I know with you there, with all your inspired goodness, I can get through anything. Will you be with me forever? We've come too far to look back now."

Clary very strongly wanted to tell Jace he'd just quoted Snow from XIII without realizing it, but decided against it. She felt as though that might have defeated the point. He was right, after all. They needed to let go of their past and parallels. Instead, she reached up and stroked Jace's cheek again. Rather cheekily, she said, "Duh. When we thought we were brother and sister, _all _we had was the idea of the present. If I wanted to jump your bones all the time then, despite my qualms, of course I'm going to want any time I can have with you now! I'd be an idiot not to take up this chance now that we don't have something like that hanging over our heads. And frankly, after the Lillith thing, I don't think our lives will ever be simple. We _really _need to make the most of the time we have."

And to get back at him for all the times he'd shut her up today, Clary kissed Jace when he was about to interrupt her. He enjoyed it for quite a bit of time, but she knew it would only be a minute before he wanted to get the last word in. She was right. "You think you're so clever," he said humorously. And then, seriously, "You really are, Clary. You make me see so much when it comes to everything. With you, I know we can get through everything. But with you, I have a reason to want to be careful in those battles. To come home to you."

And at that, Clary had to reward her Jace with a kiss. In fact, they stayed on that apartment's steps kissing for a good time. And despite how blistering hot it was, Clary's new understanding with Jace had left her feeling something else entirely. She had never felt so cool, calm, and collected in her life. And when she nestled closer into Jace's arms, she knew it'd always be the same with him. He'd always be her comfort against whatever hellish nightmares might come to take them away. In that hell, too, they would be together.

_When prayers turn to promises, not even fate can stand in their way. We held the light of hope in our hearts, and achieved the impossible. – Fang and Vanille (Final Fantasy XIII)_

**Author's Note: I came up with this idea when I was sick and delirious. This is what happens when you have Final Fantasy XIII-2 on the mind, and decide to write a Jace and Clary fic. You have the characters playing said game and realizing how similar it is, in ways, to their lives. And this is so overdue! JacexClary is one of my OTPs; The Mortal Instruments is one of my favorite book series... why did I wait so long to post something for them? **

**Actually, I know the answer to that. I've attempted many Jace and Clary stories, but never ended up finishing them for some reason. Hopefully it won't be such a problem anymore. And hopefully it wasn't too obvious I'm new to writing this fandom. **

**And, obviously, I don't own The Mortal Instruments, Final Fantasy, or anything along those lines. Though I do think Cassandra Clare might be a FF fan. That FFIX scene in the black mage village, where Zidane is telling Dagger that bedtime story, is SO much like when Jace told Clary his, "to love is to destroy" story. Actually, Zidane and Dagger are a LOT like Jace and Clary.**

**I know for a fact that Cassie's a Kingdom Hearts fan. She mentioned it in her story for Vacations From Hell (though she oddly said Kingdom Hearts II was for Xbox and seemed to think two people could play it when neither is the case). Since FF and KH kind of go hand in hand… I really believe our dear author is a fan. And I love her even more for being a KH fan since KH is my fandom!**

**Kudos, by the way, to anyone who gets all the game quotes in this!**

**Anyway, I've ranted enough. Review if you feel so inclined. Thanks for reading!**

**-Shanna**


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